Background:Irreversible cryodamage caused by oocyte vitrification limited its wild application in female fertility preservation.Antioxidants were always used to antagonist the oxidative stress caused by vitrification....Background:Irreversible cryodamage caused by oocyte vitrification limited its wild application in female fertility preservation.Antioxidants were always used to antagonist the oxidative stress caused by vitrification.However,the comprehensive mechanism underlying the protective role of antioxidants has not been studied.Procyanidin B2(PCB2)is a potent natural antioxidant and its functions in response to vitrification are still unknown.In this study,the effects of PCB2 on vitrified-thawed oocytes and subsequent embryo development were explored,and the mechanisms underlying the protective role of PCB2 were systematically elucidated.Results:Vitrification induced a marked decline in oocyte quality,while PCB2 could improve oocyte viability and further development after parthenogenetic activation.A subsequent study indicated that PCB2 effectively attenuated vitrification-induced oxidative stress,rescued mitochondrial dysfunction,and improved cell viability.Moreover,PCB2 also acts as a cortical tension regulator apart from strong antioxidant properties.Increased cortical tension caused by PCB2 would maintain normal spindle morphology and promote migration,ensure correct meiosis progression and finally reduce the aneuploidy rate in vitrified oocytes.Further study reveals that ATP biosynthesis plays a crucial role in cortical tension regulation,and PCB2 effectively increased the cortical tension through the electron transfer chain pathway.Additionally,PCB2 would elevate the cortical tension in embryo cells at morula and blastocyst stages and further improve blastocyst quality.What's more,targeted metabolomics shows that PCB2 has a beneficial effect on blastocyst formation by mediating saccharides and amino acids metabolism.Conclusions:Antioxidant PCB2 exhibits multi-protective roles in response to vitrification stimuli through mitochondria-mediated cortical tension regulation.展开更多
女性卵巢衰老远比机体其他器官衰老要早。随着人类生育年龄的推迟,卵巢衰老导致的不孕症所占比重越来越大。卵巢衰老是以卵母细胞的数量和质量下降为特征的一个自然生理过程。近年研究发现,沉默信息调节因子2(silence information regul...女性卵巢衰老远比机体其他器官衰老要早。随着人类生育年龄的推迟,卵巢衰老导致的不孕症所占比重越来越大。卵巢衰老是以卵母细胞的数量和质量下降为特征的一个自然生理过程。近年研究发现,沉默信息调节因子2(silence information regulator 2,SIRT2)介导非组蛋白和组蛋白去乙酰化,参与了卵母细胞衰老过程。哺乳动物卵泡中与年龄相关的SIRT2水平降低易致减数分裂缺陷,从而产生低质量的卵母细胞,影响妊娠结局。卵巢衰老是高龄不孕女性不可避免的自然生理过程,尽管目前辅助生殖技术为高龄不孕女性带来了福音,但低质量的卵母细胞也会影响辅助生殖技术的结局。综述SIRT2的定位、SIRT2与卵母细胞减数分裂的关系以及SIRT2在其中的主要作用,进一步介绍SIRT2介导间隙连接蛋白43(connexin 43,Cx43)、组蛋白H4第16位赖氨酸(H4K16)、α-微管蛋白(α-tubulin)、BUBR1和叉头框蛋白O3a(forkhead box O3a,FOXO3a)等蛋白质去乙酰化参与减数分裂过程所涉及的相关信号通路,为防治卵母细胞衰老提供新的思路。展开更多
Mature eggs (at metaphase Ⅱ stage) produce a series of Ca2+ oscillation at fertilization. To define whether the fertilization-induced Ca2+ oscillation is restrict to the metaphase Ⅱ eggs and cell cycle dependent, mo...Mature eggs (at metaphase Ⅱ stage) produce a series of Ca2+ oscillation at fertilization. To define whether the fertilization-induced Ca2+ oscillation is restrict to the metaphase Ⅱ eggs and cell cycle dependent, mouse oocytes at prophase Ⅰ (arrested at germinal vesicle stage),metaphase Ⅰ, metaphase Ⅱ, as well as the pronuclear embryos at interphase of the first mitotic division derived from fertilization or parthenogenetic activation were inseminated after removal of zona pellucida. The results show that the fertilization-induced Ca2+ oscillation is not specific to metaphase Ⅱ eggs. This is supported by the fact that immature oocytes generated the Ca2+ oscillations at fertilization regardless of their nuclear progression from prophase Ⅰ to metaphase Ⅰ (in vitro matured) stage. More interestingly, it was first found that pronuclear embryos at interphase derived from parthenogenetic activation showed Ca2+ oscillations in response to fertilization while the zygotes at interphase did not after reinsemination or intracytoplasmic injection of sperm extracts which induce Ca2+ oscillations in MII eggs. This suggests that the ability of oocytes to generate Ca2+ oscillation in response to sperm penetration is not regulated in a cell cycle dependent manner but dependent on the cytoplasmic maturation.展开更多
Background:CK2(casein kinase 2)is a serine/threonine-selective protein kinase that has been involved in a variety of cellular processes such as DNA repair,cell cycle control and circadian rhythm regulation.However,its...Background:CK2(casein kinase 2)is a serine/threonine-selective protein kinase that has been involved in a variety of cellular processes such as DNA repair,cell cycle control and circadian rhythm regulation.However,its functional roles in oocyte meiosis have not been fully determined.Results:We report that CK2 is essential for porcine oocyte meiotic maturation by regulating spindle assembly checkpoint(SAC).Immunostaining and immunoblotting analysis showed that CK2 was constantly expressed and located on the chromosomes during the entire oocyte meiotic maturation.Inhibition of CK2 activity by its selective inhibitor CX-4945 impaired the first polar body extrusion and arrested oocytes at M I stage,accompanied by the presence of BubR1 at kinetochores,indicative of activated SAC.In addition,we found that spindle/chromosome structure was disrupted in CK2-inhibited oocytes due to the weakened microtubule stability,which is a major cause resulting in the activation of SAC.Last,we found that the level DNA damage as assessed byγH2A.X staining was considerably elevated when CK2 was inhibited,suggesting that DNA damage might be another critical factor leading to the SAC activation and meiotic failure of oocytes.Conclusions:Our findings demonstrate that CK2 promotes the porcine oocyte maturation by ensuring normal spindle assembly and DNA damage repair.展开更多
Background： Maternal obesity alters oocytes and subsequent fetal metabolism. An increasing number of studies have shown that the endoplasmic reticulums（ER） or mitochondria have important effects on oocyte quality, ...Background： Maternal obesity alters oocytes and subsequent fetal metabolism. An increasing number of studies have shown that the endoplasmic reticulums（ER） or mitochondria have important effects on oocyte quality, but there has been no study of the effect of mitochondria-associated ER membranes（MAMs） on oocyte quality. The present study was designed to assess whether the level of MAM and MAM-related proteins were different in oocytes from obese and control mice.Results： First, oocytes from mice with high-fat-diet（HFD）-induced obesity had higher levels（either greater numbers or a higher proportion for the same numbers） of MAM than oocytes from control mice. The abundance of MAM-related proteins in oocytes from obese mice was significantly greater at both the messenger RNA and protein levels, including inositol 1,4,5-trisphosphate receptor, type 1（IP3R1）, inositol 1,4,5-trisphosphate receptor,type 2（IP3 R2） and phosphofurin acidic cluster sorting protein 2（PACS-2）. Further, there was an increase in mitochondrial Ca^（2＋）（[Ca^（2＋）]_m） which was associated with increased apoptosis and compromised cytoplasmic maturation in oocytes from obese mice. Down-regulation of MAM-related protein IP3R1 in oocytes from obese mice decreased [Ca^2＋]_mand apoptosis and improved cytoplasmic maturation but did not reduce the overal MAM level. However, down-regulating MAM-related protein PACS-2 in oocytes from obese mice did reduce the level of MAM and [Ca^（2＋）]_m, which decreased the rate of apoptosis and improved cytoplasmic maturation of oocytes from obese mice.Conclusions： It is possible that enriched MAM could increase [Ca^（2＋）]_m, and this increase has been found to be associated with increased apoptosis and compromised cytoplasmic maturation in oocytes from obese mice. This finding suggests a novel therapeutic target for obesity-induced oocyte defects.展开更多
基金National Key Research and Development Program Topics,Grant/Award Number:2021YFD1200402Chinese Universities Scientific Fund,Grant/Award Number:2021TC061+6 种基金Natural Science Foundation of Hebei province,Grant/Award Number:H2020206254Special Program for Training and Guiding Outstanding Young and Middle-aged Talents,Grant/Award Number:SKLSGIHP2021A01National Natural Science Foundation of China,Grant/Award Number:81901562&31372307Key research and development projects in Hebei province,Grant/Award Number:18226604DProgram of Young and Middle-aged Scientific and technological Innovation Leaders of the Xinjiang Production and Construction Corps,Grant/Award Number:2018CB025Xinghuo program of the First Hospital of Hebei Medical University,Grant/Award Number:XH202005The Central Guidance on Local Science and Technology Development Fund of Hebei Province,Grant/Award Number:226Z7713G。
文摘Background:Irreversible cryodamage caused by oocyte vitrification limited its wild application in female fertility preservation.Antioxidants were always used to antagonist the oxidative stress caused by vitrification.However,the comprehensive mechanism underlying the protective role of antioxidants has not been studied.Procyanidin B2(PCB2)is a potent natural antioxidant and its functions in response to vitrification are still unknown.In this study,the effects of PCB2 on vitrified-thawed oocytes and subsequent embryo development were explored,and the mechanisms underlying the protective role of PCB2 were systematically elucidated.Results:Vitrification induced a marked decline in oocyte quality,while PCB2 could improve oocyte viability and further development after parthenogenetic activation.A subsequent study indicated that PCB2 effectively attenuated vitrification-induced oxidative stress,rescued mitochondrial dysfunction,and improved cell viability.Moreover,PCB2 also acts as a cortical tension regulator apart from strong antioxidant properties.Increased cortical tension caused by PCB2 would maintain normal spindle morphology and promote migration,ensure correct meiosis progression and finally reduce the aneuploidy rate in vitrified oocytes.Further study reveals that ATP biosynthesis plays a crucial role in cortical tension regulation,and PCB2 effectively increased the cortical tension through the electron transfer chain pathway.Additionally,PCB2 would elevate the cortical tension in embryo cells at morula and blastocyst stages and further improve blastocyst quality.What's more,targeted metabolomics shows that PCB2 has a beneficial effect on blastocyst formation by mediating saccharides and amino acids metabolism.Conclusions:Antioxidant PCB2 exhibits multi-protective roles in response to vitrification stimuli through mitochondria-mediated cortical tension regulation.
文摘Mature eggs (at metaphase Ⅱ stage) produce a series of Ca2+ oscillation at fertilization. To define whether the fertilization-induced Ca2+ oscillation is restrict to the metaphase Ⅱ eggs and cell cycle dependent, mouse oocytes at prophase Ⅰ (arrested at germinal vesicle stage),metaphase Ⅰ, metaphase Ⅱ, as well as the pronuclear embryos at interphase of the first mitotic division derived from fertilization or parthenogenetic activation were inseminated after removal of zona pellucida. The results show that the fertilization-induced Ca2+ oscillation is not specific to metaphase Ⅱ eggs. This is supported by the fact that immature oocytes generated the Ca2+ oscillations at fertilization regardless of their nuclear progression from prophase Ⅰ to metaphase Ⅰ (in vitro matured) stage. More interestingly, it was first found that pronuclear embryos at interphase derived from parthenogenetic activation showed Ca2+ oscillations in response to fertilization while the zygotes at interphase did not after reinsemination or intracytoplasmic injection of sperm extracts which induce Ca2+ oscillations in MII eggs. This suggests that the ability of oocytes to generate Ca2+ oscillation in response to sperm penetration is not regulated in a cell cycle dependent manner but dependent on the cytoplasmic maturation.
基金This work was supported by the National Natural Science Foundation of China(31822053,31900592)Natural Science Foundation of Jiangsu Province(SBK2019043265)China Postdoctoral Science Foundation(2019M651849).
文摘Background:CK2(casein kinase 2)is a serine/threonine-selective protein kinase that has been involved in a variety of cellular processes such as DNA repair,cell cycle control and circadian rhythm regulation.However,its functional roles in oocyte meiosis have not been fully determined.Results:We report that CK2 is essential for porcine oocyte meiotic maturation by regulating spindle assembly checkpoint(SAC).Immunostaining and immunoblotting analysis showed that CK2 was constantly expressed and located on the chromosomes during the entire oocyte meiotic maturation.Inhibition of CK2 activity by its selective inhibitor CX-4945 impaired the first polar body extrusion and arrested oocytes at M I stage,accompanied by the presence of BubR1 at kinetochores,indicative of activated SAC.In addition,we found that spindle/chromosome structure was disrupted in CK2-inhibited oocytes due to the weakened microtubule stability,which is a major cause resulting in the activation of SAC.Last,we found that the level DNA damage as assessed byγH2A.X staining was considerably elevated when CK2 was inhibited,suggesting that DNA damage might be another critical factor leading to the SAC activation and meiotic failure of oocytes.Conclusions:Our findings demonstrate that CK2 promotes the porcine oocyte maturation by ensuring normal spindle assembly and DNA damage repair.
基金supported by the National Basic Research Program of China[grant number 2014CB138500]
文摘Background： Maternal obesity alters oocytes and subsequent fetal metabolism. An increasing number of studies have shown that the endoplasmic reticulums（ER） or mitochondria have important effects on oocyte quality, but there has been no study of the effect of mitochondria-associated ER membranes（MAMs） on oocyte quality. The present study was designed to assess whether the level of MAM and MAM-related proteins were different in oocytes from obese and control mice.Results： First, oocytes from mice with high-fat-diet（HFD）-induced obesity had higher levels（either greater numbers or a higher proportion for the same numbers） of MAM than oocytes from control mice. The abundance of MAM-related proteins in oocytes from obese mice was significantly greater at both the messenger RNA and protein levels, including inositol 1,4,5-trisphosphate receptor, type 1（IP3R1）, inositol 1,4,5-trisphosphate receptor,type 2（IP3 R2） and phosphofurin acidic cluster sorting protein 2（PACS-2）. Further, there was an increase in mitochondrial Ca^（2＋）（[Ca^（2＋）]_m） which was associated with increased apoptosis and compromised cytoplasmic maturation in oocytes from obese mice. Down-regulation of MAM-related protein IP3R1 in oocytes from obese mice decreased [Ca^2＋]_mand apoptosis and improved cytoplasmic maturation but did not reduce the overal MAM level. However, down-regulating MAM-related protein PACS-2 in oocytes from obese mice did reduce the level of MAM and [Ca^（2＋）]_m, which decreased the rate of apoptosis and improved cytoplasmic maturation of oocytes from obese mice.Conclusions： It is possible that enriched MAM could increase [Ca^（2＋）]_m, and this increase has been found to be associated with increased apoptosis and compromised cytoplasmic maturation in oocytes from obese mice. This finding suggests a novel therapeutic target for obesity-induced oocyte defects.
